FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL
Specification
(See section 10 and rule 13)
POWER SOURCES
KIRLOSKAR BROTHERS LTD.,
an Indian Company
of Udyog Bhavan, Tilak Road, Pune 411 002, Maharashtra, India
THE FOLLOWING SPEC IFICATION DESCRIBES THE INVENTION.

This invention relates to the field of power sources.
In particular this invention relates to alternating current power sources.
Still particularly, this invention relates to power sources providing converted alternating current power sources where a primary DC source is converted to an AC supply.
A particular feature of this invention is the conversion of variable or fluctuating DC power to an AC power normally referred to as inversion.
This invention is particularly useful for converting Solar energy directly into AC Power which is useful for running an appliance or equipment that is in need of such power.
In the prior art use of solar panels for converting incident solar energy to DC voltage is known. Typically, photvoltaic cells convert incident light to a DC voltage which is stored in batteries. These batteries are connected to an inverter for obtaining AC power. Not only is such equipment bulky. But the losses in the process makes the whole system uneconomical.
This invention envisages a system by which DC voltage obtained from a set of solar panels is converted to either a single phase or a three phase AC voltage using a compact device having a simple switching operation between the two modes of power options.


The invention discloses a solar controller power source that converts variable DC solar input into a three phase A/C power source which can run a pump or single phase 50 Hz A/C which can take lights and fan load without battery.
The scheme of the device is shown in figure 1 of the drawings which is self explanatory.
The operation of the system of this invention can be explained as follows:
The system includes a start switch.
There are three positions in the START switch :
0 - The controller is in programming mode and facilitates changing of operating parameters with the help of an external programmer connected to the controller.
1 - The controller can be started to deliver single phase 50 Hz AC voltage for lighting and small inductive equipment such as fans and the like.
2 - The controller can be started to deliver three phase variable frequency output for driving large inductive loads.
When the START switch selector is in ' 1' position i.e. Single Phase, it first compares the available DC voltage with the DC low (preset in controller). If the available DC voltage is less than or equal to DC low, it does not start the further operation and continues comparing the available DC voltage with DC low. If the available DC voltage is more than DC low, it converts the DC voltage to single phase, 50 Hz AC voltage and


enables the SPWM in the Digital Signal Processor (DSP). At the same time, it disables the SVPWM in DSP.
DSP sends signals to Switching Power Module and supplies single phase, 50 Hz, AC output, which can be used for lighting and running domestic appliances.
When the START switch selector is in '2 position i.e. Three Phase, it delays the processing for a preset time. At this time, it disables the SPWM. After the delay, it slowly starts and enables SVPWM. It compares the available DC voltage with the DC low (preset in controller). If the available DC voltage is less than or equal to DC low, it disables SVPWM. If the available DC voltage is more than DC low, it compares the DC voltage with the reference voltage set in controller. If the DC voltage is more than reference voltage, output frequency is increased in step of 1 Hz and if the DC voltage is less than reference voltage, output frequency is decreased in step of 1 Hz. These signals will be sent to SVPWM, which will generate drive pulse and drive the IGBT in Switching Power Module. Three phase AC variable frequency power will be available at U, V, W terminals of the Switching Power Module.
The novel features of this invention is :
1. It utilizes same Switching Power Module for generating three phase variable frequency AC power output and single phase fixed frequency (50 Hz) AC power output.
2. When driving a load typically a pump using solar modules, the reference voltage referred above is derived from maximum power


point voltage specified by the solar module manufacturer. The output frequency is instantaneously adjusted with the available power from the solar modules at varying sun intensity to match the power drawn by the pump.
While considerable emphasis has been placed herein on the particular features of the preferred embodiment and the improvisation with regards to it, it will be appreciated the various modifications can be made in the preferred embodiments without departing from the principles of the invention. These and the other modifications in the nature of the invention will be apparent to those skilled in art from disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to interpreted merely as illustrative of the invention and not as a limitation.